原创 VHDL按键写法（含按键消抖和弹起检测)

PROCESS(clk,rst)
 variable keys   : integer range 0 to 100000;--按键消抖变量
begin
 if(rst='0')then
  ";
 elsif(clk'event and clk='1')then
  if(key(2)='0')then
   if(keys=100000 and key(2)='0')then
    key_c<='1';
    keys:=0;
   else
    keys:=keys+1;
   end if;
  end if;
  if(key_c='1' and key(2)='1')then
   if(keys=100000 and key(2)='1')then
    key_c<='0';
    keys:=0;
    if(key_state="101")then
     key_state<="000";
    else
     key_state<=key_state+1;
    end if;
   else
    keys:=keys+1;
   end if;
  end if;
 end if;
end PROCESS;